The UK Government is reported to be considering using satellite technology to control the speed of cars on the streets. Under the system, motorists would be automatically limited according to the local speed restriction.

While electric cars are still struggling along in the slow lane, electronically-controlled cars are moving into the fast lane.

One of the latest features is the satellite-based Global Positioning System (GPS) which directs drivers from A to B via electronic maps in their vehicles.

And now researchers at Leeds University and the Motor Industry Research Association (Mira) have proposed using the system to limit speeds on Britain's roads.

Spy in the sky: GPS satellites are the key to speed control system

GPS is the key element in their Intelligent Speed Adaptation (Isa) system, and allows you to find your exact position on the Earth to within an accuracy of one metre.

The researchers found GPS can be linked to a vehicle's electronic engine management, thereby controlling fuel supply, ignition and braking.

So just as a driver enters a 30mph zone, the vehicle's speed is cut accordingly.

Global Positioning System

The first GPS satellite was launched in 1978

Twenty four GPS satellites orbit at 12,500 miles above the Earth and are continuously monitored by ground stations

GPS satellites around the globe transmit signals that can be detected by anyone with a GPS receiver

GPS was designed originally as a military aid, but it soon got taken up in civilian life

During construction of the Channel Tunnel, engineers relied on GPS receivers to make sure they met exactly in the middle

Research project leader Mark Fowkes of Mira, told BBC News Online: "The satellite is just giving the system the car's place on the map. Isa tells it what to do."

The researchers originally thought electronic signals from speed signs would do the same job as GPS.

But Mr Fowkes said: "There are an awful lot of speed limit signs, so that would have been very expensive.

"With GPS becoming more widely available, it seemed an obvious step to make."

Early in-car GPS systems were notoriously inaccurate, but Mr Fowkes said the technology was now sufficiently advanced for it to pinpoint cars accurately enough for use in speed reduction.

He admitted that manufacturers, who sell many cars on their ability to exceed the speed limit, may not be keen to introduce such a system in their cars.

However, in the 1997 Master project, financed by the European Union, a field study was carried out in Sweden, the Netherlands and Spain with a car equipped with an automatic speed limiter.

Twenty people in each country test drove the car and half said they would accept the limiter voluntarily in their own vehicles.

Mr Fowkes admitted it could be difficult getting systems imposed on car drivers, without an override system to turn it off.